A seat pad for an automobile is formed by foaming an expandable resin material such as urethane in a mold. A resin foam made of the expandable urethane composes a body of the seat pad. On the back or the inside of the seat pad body, a member (an embedment member) such as a member for controlling the sitting comfort (for example, a member for controlling the hardness or the holding property) is integrally provided.
The embedment member of the seat pad is generally attached to a core of the mold so that the embedment member is integrated by foaming of the resin such as urethane.
A conventional example of the method of forming a foamed resin article will be described with reference to FIGS. 5 through 8.
As shown in FIGS. 5 through 7, a mold (metal mold) comprises a lower mold half 1, an upper mold half 2, and a core 3 attached to the upper mold half 2. The upper mold half 2 is pivotable about a pivot (not shown) upwardly and downwardly as shown in FIG. 7. The core 3 is provided with a pin-like projection 4 at such a position that the projection 4 projects downwardly when the upper mold half 2 is clamped.
To form a seat pad using this mold, a seat pad embedment member 5 is attached to and skewered with the projection 4 and an predetermined amount of expandable resin material such as urethane liquid is supplied into the lower mold half 1. After that, the upper mold half 2 is clamped (FIG. 5) and the resin is foamed (FIG. 6). After the resin foam is cured, the upper mold half 2 is pivotally moved to stand vertically as shown in FIG. 7 and a seat pad 7 in which a seat pad body 6 composed of the resin foam and the seat pad embedment member 5 are integrated is released from the mold. After taking out the seat pad 7, another seat pad embedment member 5 is skewered with the pin-like projection 4 while the upper mold half 2 is kept in the standing state, thereby serving the forming process for another seat pad.
FIG. 8 is a vertical sectional view of the seat pad 7 thus formed in which the left side of this drawing is the front side of the seat.
It is well known in the art to from a seat pad by foaming with a mold as shown in JP S61-37101B.
In the forming method shown in FIGS. 5 through 7, the formed seat pad 7 must be released from the mold in a substantially horizontal direction (in the leftward direction of FIG. 7) H. This is because the seat pad embedment member 5 is skewered with the pin-like projection 4 so that it is impossible to release the seat pad 7 from the mold in the upward direction (direction Z) of FIG. 7. It should be noted that the direction Z is a direction toward the front side of the seat for the seat pad 7.
For releasing the seat pad 7 from the mold in the direction H, it is required to jerk a front lower portion 6a (FIG. 8) of the seat pad body 6 off the core 3. If it is possible to release the seat pad from the mold in the direction Z, such jerking operation is not required, thus facilitating the releasing operation.